Clinical trial design, nasal allergen challenge models, and considerations of relevance to pediatrics, nasal polyposis, and different classes of medication

Within clinical trial design, there are important questions to be considered in relationship to the therapeutic intervention. Should this be given topically or systemically? What are the appropriate timing and frequency of medication? Does the disease itself modify the treatment efficacy, and does combination therapy afford better clinical outcome than single-modality therapy? These issues are discussed, and the influences of current therapies on objective outcome measures in allergic rhinitis are reviewed.